JP5708566B2 - Electromagnetic coupling - Google Patents

Description

  The present invention relates to an electromagnetic coupling that transmits rotation from a drive shaft to a driven shaft.

  As a coupling (shaft coupling) that transmits rotation from a drive shaft to a driven shaft, an electromagnetic coupling that transmits rotation from the drive shaft to the driven shaft by electromagnetic action is known.

  For example, Patent Document 1 discloses an electromagnetic coupling 100 as shown in FIG. The electromagnetic coupling 100 includes a first rotor 101 and a second rotor 102. The first rotor 101 has a cylindrical shape, and a permanent magnet is provided on the outer peripheral surface thereof. The second rotor 102 has a substantially cylindrical shape, and the first rotor 101 is inserted into the hollow portion. The second rotor 102 is provided with a magnetic path 106 made of a highly permeable material in a structure 104 having low permeability. As shown in FIG. 17, two magnetic paths 106 (one pair) are provided in the circumferential direction of the second rotor 102, and three pairs (three pairs) are provided along the rotation axis direction of the second rotor 102. ) Is provided.

  The first rotor 101 and the second rotor 102 are accommodated in a housing 107. A core 110 around which a coil 108 is wound is provided at a portion of the housing 107 facing the second rotor 102. By passing a current through the coil, a magnetic flux is generated around the coil 108. The magnetic path 106 is magnetized by the magnetic flux passing through the magnetic path 106 of the second rotor 102.

  When the first rotor 101 rotates in this state, the permanent magnet provided in the first rotor 101 and the magnetized second rotor 102 attract each other, and the second rotor 102 also rotates. In this way, the rotation of the first rotor 101 is transmitted to the second rotor 102.

  Further, by supplying an alternating current to the coil 108, a rotating magnetic field is generated around the coil 108. By applying a rotating magnetic field to the second rotor 102, the second rotor 102 can be rotated at a different rotational speed from that of the first rotor 101. For example, by applying a rotating magnetic field to the second rotor 102 along the direction of rotation of the first rotor 101, the rotational speed of the second rotor 102 increases from the rotational speed of the first rotor 101.

  Non-Patent Document 1 discloses a motor that uses an electromagnet instead of using a permanent magnet.

JP 2008-245484 A

Toshie Takeuchi, “EV / HEV parts dissection 10th”, Nikkei Automotive Technology, Nikkei BP, January 1, 2011, No. 22, p. 102-105

  By the way, when the proportion of the magnetic path of the rotor to which the rotating magnetic field is applied is small, the magnetic coupling force with the other rotor may be weakened. Therefore, an object of the present invention is to provide an electromagnetic coupling that can increase the magnetic coupling force between the rotors as compared with the conventional one.

  The present invention relates to an electromagnetic coupling. The electromagnetic coupling includes a stator around which a coil that generates a rotating magnetic field is wound. Further, a first pole tooth that is provided on the outer peripheral side of the stator so as to be rotatable with respect to the stator and that serves as one magnetic pole of the rotating magnetic field, and a second pole tooth that serves as the other magnetic pole, First rotors are provided alternately along the direction. Furthermore, a second rotor is provided on the outer peripheral side of the first rotor so as to be rotatable with respect to the first rotor, and a plurality of permanent magnets are arranged along the circumferential direction. Furthermore, the detection unit that detects the rotation of the first and second rotors, and the rotation magnetic field is changed by changing the current supplied to the coil, so that the first rotor and the second rotor A control unit for controlling the relative rotational speed of the motor. Further, the first rotor includes a first pole tooth ring in which a plurality of the first pole teeth are provided in the circumferential direction at intervals, and a plurality of the second pole teeth are provided in the circumferential direction at intervals. And a second pole tooth ring disposed to face the first pole tooth ring so that the second pole tooth is disposed in a gap between the adjacent first pole teeth.

  In the above invention, it is preferable that a plurality of the stator, the first rotor, and the second rotor are provided along a rotation axis direction of the first rotor.

  Moreover, in the said invention, it is suitable that the said stator, the said 1st rotor, and the said 2nd rotor are respectively provided along the rotating shaft direction of the said 1st rotor.

  The electromagnetic coupling according to the present invention includes a stator formed in a cylindrical shape and wound with a coil that generates a rotating magnetic field. Furthermore, it is formed in a cylindrical shape, and is provided on the inner peripheral side of the stator so as to be rotatable with respect to the stator. The first pole tooth that is one magnetic pole of the rotating magnetic field and the second magnetic pole that is the other magnetic pole Two pole teeth are provided with the first rotor provided alternately along the circumferential direction. Furthermore, a second rotor is provided on the inner peripheral side of the first rotor so as to be rotatable with respect to the first rotor, and a plurality of permanent magnets are arranged along the circumferential direction. Furthermore, the detection unit that detects the rotation of the first and second rotors, and the rotation magnetic field is changed by changing the current supplied to the coil, so that the first rotor and the second rotor A control unit for controlling the relative rotational speed of the motor. Further, the first rotor includes a first pole tooth ring in which a plurality of the first pole teeth are provided in the circumferential direction at intervals, and a plurality of the second pole teeth are provided in the circumferential direction at intervals. And a second pole tooth ring disposed to face the first pole tooth ring so that the second pole tooth is disposed in a gap between the adjacent first pole teeth.

  According to the present invention, the magnetic coupling force between the rotors can be made stronger than before.

It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on this Embodiment. It is a disassembled perspective view which illustrates the component of the electromagnetic coupling which concerns on this Embodiment. It is a partial cross section which illustrates the electromagnetic coupling which concerns on this Embodiment. It is front sectional drawing which illustrates the electromagnetic coupling which concerns on this Embodiment. It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on the other form of this embodiment. It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on the other form of this embodiment. It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on the other form of this embodiment. It is a figure explaining arrangement | positioning of the pole tooth of the electromagnetic coupling which concerns on the other form of this Embodiment. It is a figure explaining the electric power supply to the electromagnetic coupling which concerns on the other form of this Embodiment. It is a figure explaining the electric power supply to the electromagnetic coupling which concerns on the other form of this Embodiment. It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on the other form of this embodiment. It is side surface sectional drawing which illustrates the electromagnetic coupling which concerns on the other form of this embodiment. It is a figure explaining arrangement | positioning of the pole tooth of the electromagnetic coupling which concerns on the other form of this Embodiment. It is a figure explaining the electric power supply to the electromagnetic coupling which concerns on the other form of this Embodiment. It is a figure explaining the electric power supply to the electromagnetic coupling which concerns on the other form of this Embodiment. It is side surface sectional drawing which illustrates the conventional electromagnetic coupling. It is a perspective view which illustrates the conventional electromagnetic coupling.

  FIG. 1 illustrates a side cross-sectional view of an electromagnetic coupling 10 according to the present embodiment. The electromagnetic coupling 10 includes a stator 12, a first rotor 14, a second rotor 16, a detection unit 18, and a control unit 20.

  A coil 22 that generates a rotating magnetic field is wound around the stator 12. The stator 12 may have a columnar shape or a cylindrical shape. Further, flanges may be formed at both ends of the stator 12 in order to prevent the coil 22 from jumping out in the central axis direction of the stator 12. The stator 12 may be made of a highly permeable material, for example, iron. The stator 12 may be fixed to fixing means such as a casing (not shown).

  The second rotor 16 is provided on the outer peripheral side of the first rotor 14 and is rotatable with respect to the first rotor 14. For example, an air gap AG <b> 1 may be provided between the first rotor 14 and the second rotor 16 so that the first rotor 14 and the second rotor 16 are not in contact with each other, or the first rotor 14. A bearing or the like may be provided between the first rotor 16 and the second rotor 16.

  As shown in FIG. 2, the second rotor 16 has a cylindrical shape, and a plurality of permanent magnets 30 are arranged on the inner peripheral surface along the circumferential direction. The permanent magnets 30 may be arranged so that the magnetic poles (N pole and S pole) are alternately changed along the circumferential direction.

  Returning to FIG. 1, the second rotor 16 may be connected to the drive source side rotation shaft 26 connected to the drive source 28. The drive source 28 may be a vehicle internal combustion engine or a rotating electrical machine. The rotation of the drive source 28 is transmitted to the drive source side rotation shaft 26, whereby the second rotor 16 is rotated.

  The detection unit 18 detects the rotation of the first rotor 14 and the second rotor 16. The detection unit 18 may be a rotation angle sensor such as a resolver or a rotary encoder, for example. The rotation angles of the first rotor 14 and the second rotor 16 detected by the detection unit 18 are transmitted to the control unit 20.

  The control unit 20 controls the relative rotational speed between the first rotor 14 and the second rotor 16. The control unit 20 controls the relative rotational speed between the second rotor 16 and the first rotor 14 by changing the current supplied to the coil 22 and changing the rotating magnetic field of the coil 22. This rotation control will be described later. Further, the control unit 20 obtains the rotation direction from the rotation angle of the first rotor 14 detected by the detection unit 18 and controls the current so as to give a rotating magnetic field suitable for the rotation direction. The control unit 20 may be a computer including an arithmetic circuit such as a CPU, for example.

  The first rotor 14 is provided on the outer peripheral side of the stator 12 and is rotatable with respect to the stator 12. For example, an air gap AG <b> 2 may be provided between the stator 12 and the first rotor 14 so as not to be in contact, or a bearing or the like may be provided between the stator 12 and the first rotor 14.

  Further, the first rotor 14 may be connected to a load-side rotating shaft 34 that is connected to the load 32. The load 32 may be a vehicle wheel, for example. The rotation of the first rotor 14 is transmitted to the load side rotation shaft 34, and the rotation is transmitted to the load 32 accordingly.

  The first rotor 14 may have a cylindrical shape. The first rotor 14 includes a first pole tooth 36 and a second pole tooth 38. A plurality of first pole teeth 36 and second pole teeth 38 are alternately provided along the circumferential direction. The first pole tooth 36 functions as one magnetic pole (one of N and S poles) of the rotating magnetic field generated from the coil 22, and the second pole tooth 38 is the other magnetic pole (the other of the N pole and the S pole). ).

  Here, the first rotor 14 may be configured by combining a member provided with the first pole teeth 36 and a member provided with the second pole teeth 38. For example, as shown in FIG. 2, the first rotor 14 is configured by combining a first pole tooth ring 40 provided with first pole teeth 36 and a second pole tooth ring 42 provided with second pole teeth 38. You may make it comprise.

  The first pole tooth ring 40 may be a ring-shaped member in which a plurality of first pole teeth 36 are formed in the circumferential direction at intervals. Similarly, the second pole tooth ring 42 may be a ring-shaped member in which a plurality of second pole teeth 38 are formed in the circumferential direction at intervals. Further, the interval between the adjacent first pole teeth 36 in the first pole tooth ring 40 may be slightly wider than the circumferential width of the second pole teeth 38. Similarly, the interval between the adjacent second pole teeth 38 in the second pole tooth ring 42 may be slightly wider than the circumferential width of the first pole teeth 36.

  The first rotor 14 is configured by combining the first pole tooth ring 40 and the second pole tooth ring 42 facing each other. At this time, it is preferable that the second pole teeth 38 are arranged in the gap between the adjacent first pole teeth 36. At this time, it is preferable that no magnetic path is formed between the first pole tooth ring 40 and the second pole tooth ring 42. For example, an air gap is provided between the first pole tooth 36 and the second pole tooth 38, or a non-magnetic material such as resin or aluminum is provided between the first pole tooth 36 and the second pole tooth 38. The material may be filled. The non-magnetic material may be a material having a magnetic permeability of 10.0 or less, for example. Moreover, you may connect the 1st pole tooth ring 40 and the 2nd pole tooth ring 42 with the fastening member which consists of a non-permeable material.

  FIG. 3 shows how the first pole teeth 36 and the second pole teeth 38 are magnetized by the magnetic field generated from the coil 22. When a current is supplied to the coil 22, a magnetic flux indicated by a broken line is generated around the coil 22. This magnetic flux passes through the stator 12 and the air gap AG2 and reaches the first pole teeth 36 and the second pole teeth 38. Here, as shown in FIG. 3, since no magnetic path is formed between the first pole tooth 36 and the second pole tooth 38, one pole tooth acts as one magnetic pole. Then, the other pole tooth acts as the other magnetic pole. By alternately arranging the first pole teeth 36 and the second pole teeth 38, one magnetic pole and the other magnetic pole are alternately arranged.

  Control of the relative rotational speed between the first rotor 14 thus magnetized and the second rotor 16 including the permanent magnet 30 will be described with reference to FIG. FIG. 4 illustrates a front cross-sectional view of the electromagnetic coupling 10. This figure shows a case where the second rotor 16 is rotated clockwise as viewed from the drawing in response to the rotational force from the drive source 28.

The torque on the input side for inputting the rotational force is indicated by T _in , the rotational speed is indicated by N _in , the torque on the output side is indicated by T _out , and the rotational speed is indicated by N _out . In the example of FIG. 4, the torque of the first rotor 14 becomes T _{out and} the torque of the second rotor 16 becomes T _in . Further, the output (power [W]) from the coil 22 is indicated by P _mg . Regarding the output on the input side (T × N [W]), the output on the output side, and the output by the coil 22, the relationship shown in the following Equation 1 is obtained.

[Equation 1]
T _in × N _in + P _mg = T _out × N _out

Here, the second rotor 16 tries to apply a clockwise torque to the first rotor 14. At this time, counterclockwise torque is generated in the first rotor 14 due to the relationship of action and reaction. From the balance of force, the torque of both is equal. Therefore, T _in = T _out . From Equation 1, by changing the power P _mg , the input side rotational speed N _in and the output side rotational speed N _out are made different, in other words, relative rotation between the first rotor 14 and the second rotor 16. The number can be changed.

For example, when the input side is the second rotor 16, the control unit 20 receives the rotation speed N _in of the second rotor 16 from the detection unit 18. Further, the input and the like operator, such as by pre-stored command value, and sets the rotational speed N _out of the first rotor 14. The control unit 20 calculates the difference between the rotational speed N _in of the second rotor 16 and the rotational speed N _out of the first rotor 14 and obtains the electric power P _mg corresponding to this difference based on Equation 1. The control unit 20 supplies the obtained power P _mg to the coil 22.

Further, when the rotations of the first rotor 14 and the second rotor 16 are to be synchronized (N _in = N _out ), a direct current is supplied to the coil 22 so that the work by the coil 22 is reduced to zero. Good.

Further, when the output side rotational speed N _OUT is lower than the input side rotational speed N _in , the power P _mg takes a negative value. That is, regenerative power can be obtained by making the output side rotational speed N _OUT lower than the input side rotational speed N _in . Therefore, the coil 22 may be connected to a power converter such as an AC / DC converter or a power storage means such as a battery.

  In the above-described embodiment, the first rotor 14 is disposed so as to face only the outer peripheral surface of the stator 12, but the present invention is not limited to this configuration. For example, as shown in FIG. 5, the length of the first rotor 14 in the direction of the rotational axis is made longer than that of the stator 12, and the first rotor 14 is shaped so as to cover the end surface of the stator 12 in the direction of the rotational axis. The rotor 14 may be configured. By doing so, it is possible to increase the magnetic flux passing through the first rotor 14.

  In the above-described embodiment, the first rotor 14 and the second rotor 16 are arranged from the stator 12 toward the outer peripheral side, but the present invention is not limited to this configuration. For example, as shown in FIG. 6, the first rotor 14 and the stator 12 may be arranged from the second rotor 16 toward the outer periphery side.

  In the electromagnetic coupling 10 shown in FIG. 6, the stator 12 is provided on the outermost periphery side. The stator 12 may be configured in a cylindrical shape, and the coil 22 may be wound around the inner peripheral surface thereof. Further, the first rotor 14 may be provided on the inner peripheral side of the stator 12. Similarly to the stator 12, the first rotor 14 may also be configured in a cylindrical shape. The 2nd rotor 16 may be provided in the inner peripheral side of the 1st rotor 14, The shape may be a column shape. Further, the permanent magnet 30 may be provided on the outer peripheral surface of the second rotor 16 so as to face the first rotor 14.

  Further, as a configuration in which a rotating magnetic field is effectively applied to the first rotor 14, AC power may be supplied to the coil 22 in a double phase. FIG. 7 illustrates an electromagnetic coupling 10 that can supply three-phase AC power. The stators 12A to 12C, the first rotors 14A to 14C, and the second rotors 16A to 16C are provided in three along the rotation axis direction. The first rotors 14A to 14C may be connected to each other by a non-magnetic connecting member (not shown). The second rotors 16A to 16C may be connected to each other by a permeable or non-permeable connecting member.

  The arrangement of the first pole teeth 36 and the second pole teeth 38 of the first rotors 14A to 14C may be in accordance with the three-phase AC power supplied to the stators 12A to 12C. FIG. 8 illustrates a state in which the cylindrical first rotors 14A to 14C are opened on a plane. Here, the number of pole pairs in the first rotor 14 is three. The first pole teeth 36 and the second pole teeth 38 of the first rotors 14A to 14C are arranged so as to be shifted in the circumferential direction at intervals of 120 ° in electrical angle.

FIGS. 9 and 10 illustrate states of currents and voltages supplied to the stators 12A to 12C when the first pole teeth 36 and the second pole teeth 38 are arranged as described above. FIG 9, the rotational speed N _out of the output side when the rotation greater than the number N _in the input side (N _in <N _out), i.e. during power running of the electric current, state of voltage is illustrated. The symbols U, V, and W shown in the graph indicate the voltage or current applied to each of the stators 12A to 12C. The upper part of FIG. 9 shows a state in which a back electromotive voltage is generated when there is no load. In this state, as shown in the lower part of FIG. 9, a current having the same phase as the voltage is supplied. As a result, a rotating magnetic field in the same direction as the rotation direction of the input shaft is applied to the first rotor 14, and the output-side rotation speed N _out is correspondingly increased from the input-side rotation speed N _in .

FIG. 10 illustrates the state of current and voltage when the output side rotational speed N _out is smaller than the input side rotational speed N _in (N _in > N _out ), that is, regeneration. When back electromotive force is generated as shown in the upper part of FIG. 10, a current having a phase opposite to that of the power waveform is supplied. Since the voltage and current are in opposite phases, the power that is the product of the voltage and current is 0 or a negative value. The supplied power becomes negative, that is, regenerative power can be obtained.

  As shown in FIG. 11, when the stator 12 has a three-phase structure, the magnetic field of the center stator 12B is weakened (interfered) by the magnetic fields of the adjacent stators 12A and 12C. As a result, the magnetic field of the center stator 12B may be weaker than the magnetic fields of the adjacent stators 12A and 12C. For example, the maximum value of the magnetic field strength may be nonuniform between the stators 12A and 12C and the stator 12B.

  Therefore, as shown in FIG. 12, the stator 12 may have a two-phase structure. The stators 12A and 12B, the first rotors 14A and 14B, and the second rotors 16A and 16B are each provided in two along the rotation axis direction. Similarly to the three-phase structure, the first rotors 14A and 14B may be connected to each other by a non-magnetic connecting member (not shown). The second rotors 16A and 16B may be connected to each other by a permeable or non-permeable connecting member.

  The magnetic field generated from the stator 12A is weakened by the magnetic field of the stator 12B, but the magnetic field of the stator 12B is also weakened by the magnetic field of the stator 12A. As a result, the maximum value of the magnetic field strength is approximately equal between both stators.

  FIG. 13 illustrates a state in which the cylindrical first rotors 14A and 14B are opened on a plane. Here, in order to facilitate the comparison with the three-phase structure, the number of pole pairs in the first rotor 14 is three. The first pole teeth 36 and the second pole teeth 38 of the first rotors 14A and 14B are arranged so as to be shifted in the circumferential direction at intervals of 90 ° in electrical angle.

FIGS. 14 and 15 illustrate the states of current and voltage supplied to the stators 12A and 12B when the first pole teeth 36 and the second pole teeth 38 are arranged as described above. 14, the rotational speed N _out of the output side when the rotation greater than the number N _in the input side (N _in <N _out), i.e. during power running of the electric current, state of voltage is illustrated. The symbols A and B shown in the graph indicate the voltage or current applied to each of the stators 12A and 12B. The upper part of FIG. 14 shows a state where a back electromotive voltage is generated when there is no load. In this state, as shown in the lower part of FIG. 14, a current having the same phase as the voltage is supplied. As a result, a rotating magnetic field in the same direction as the rotation direction of the input shaft is applied to the first rotor 14, and the output-side rotation speed N _out is correspondingly increased from the input-side rotation speed N _in .

FIG. 15 illustrates the state of the current and voltage when the output side rotational speed N _out is smaller than the input side rotational speed N _in (N _in > N _out ), that is, regeneration. When back electromotive force is generated as shown in the upper part of FIG. 15, a current having a phase opposite to that of the power waveform is supplied. Since the voltage and current are in opposite phases, the power, which is the product of the voltage and current, is 0 or a negative value, and thus regenerative power can be obtained.

  DESCRIPTION OF SYMBOLS 10 Electromagnetic coupling, 12 Stator, 14 1st rotor, 16 2nd rotor, 18 Detection part, 20 Control part, 22 Coil, 26 Drive source side rotating shaft, 28 Drive source, 30 Permanent magnet, 32 Load, 34 Load side rotating shaft, 36 1st pole tooth, 38 2nd pole tooth, 40 1st pole tooth ring, 42 2nd pole tooth ring, 100 electromagnetic coupling, 101 1st rotor, 102 2nd Rotor, 104 structure, 106 magnetic path, 107 housing, 108 coil, 110 core.

Claims (4)

A stator around which a coil for generating a rotating magnetic field is wound;
A first pole tooth serving as one magnetic pole of the rotating magnetic field and a second pole tooth serving as the other magnetic pole are provided on the outer circumferential side of the stator in a circumferential direction. First rotors arranged alternately along,
A second rotor provided on the outer peripheral side of the first rotor so as to be rotatable with respect to the first rotor, and a plurality of permanent magnets arranged along the circumferential direction;
A detector for detecting rotation of the first and second rotors;
A control unit that controls a relative rotational speed between the first rotor and the second rotor by changing the rotating magnetic field by changing a supply current to the coil;
With
The first rotor is
The length in the rotation axis direction is longer than that of the stator, and the rotation axis direction end surface of the stator is formed to be covered.
A first pole tooth ring provided with a plurality of the first pole teeth in the circumferential direction at intervals;
A plurality of the second pole teeth are provided in the circumferential direction at intervals, and the second pole teeth are arranged so that the second pole teeth are disposed in a gap between the adjacent first pole teeth. A second pole tooth ring arranged oppositely;
An electromagnetic coupling comprising: The electromagnetic coupling according to claim 1,
An electromagnetic coupling, wherein a plurality of the stator, the first rotor, and the second rotor are provided along a rotation axis direction of the first rotor. The electromagnetic coupling according to claim 2,
An electromagnetic coupling, wherein two each of the stator, the first rotor, and the second rotor are provided along a rotation axis direction of the first rotor. A stator formed in a cylindrical shape and wound with a coil that generates a rotating magnetic field;
It is formed in a cylindrical shape, is provided on the inner peripheral side of the stator so as to be rotatable with respect to the stator, and has a first pole tooth serving as one magnetic pole of the rotating magnetic field and a second pole serving as the other magnetic pole. A first rotor in which pole teeth are alternately provided along the circumferential direction;
A second rotor provided on the inner peripheral side of the first rotor so as to be rotatable with respect to the first rotor, and a plurality of permanent magnets arranged along the circumferential direction;
A detector for detecting rotation of the first and second rotors;
A control unit that controls a relative rotational speed between the first rotor and the second rotor by changing the rotating magnetic field by changing a supply current to the coil;
With
The first rotor is
A length of the rotation axis direction is made longer than that of the stator, and the rotation axis direction end surface of the stator is formed to be covered. Further, a plurality of the first pole teeth are provided in the circumferential direction at intervals. A plurality of pole teeth rings and a plurality of second pole teeth are provided in the circumferential direction with a space therebetween, and the first pole teeth are arranged in a gap between the adjacent first pole teeth. An electromagnetic coupling comprising: a second pole tooth ring disposed opposite to the pole tooth ring.

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